summaryrefslogtreecommitdiff
path: root/builtin-revert.c
diff options
context:
space:
mode:
Diffstat (limited to 'builtin-revert.c')
-rw-r--r--builtin-revert.c420
1 files changed, 420 insertions, 0 deletions
diff --git a/builtin-revert.c b/builtin-revert.c
new file mode 100644
index 0000000..e219859
--- /dev/null
+++ b/builtin-revert.c
@@ -0,0 +1,420 @@
+#include "cache.h"
+#include "builtin.h"
+#include "object.h"
+#include "commit.h"
+#include "tag.h"
+#include "wt-status.h"
+#include "run-command.h"
+#include "exec_cmd.h"
+#include "utf8.h"
+#include "parse-options.h"
+#include "cache-tree.h"
+
+/*
+ * This implements the builtins revert and cherry-pick.
+ *
+ * Copyright (c) 2007 Johannes E. Schindelin
+ *
+ * Based on git-revert.sh, which is
+ *
+ * Copyright (c) 2005 Linus Torvalds
+ * Copyright (c) 2005 Junio C Hamano
+ */
+
+static const char * const revert_usage[] = {
+ "git-revert [options] <commit-ish>",
+ NULL
+};
+
+static const char * const cherry_pick_usage[] = {
+ "git-cherry-pick [options] <commit-ish>",
+ NULL
+};
+
+static int edit, no_replay, no_commit, mainline;
+static enum { REVERT, CHERRY_PICK } action;
+static struct commit *commit;
+
+static const char *me;
+
+#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
+
+static void parse_args(int argc, const char **argv)
+{
+ const char * const * usage_str =
+ action == REVERT ? revert_usage : cherry_pick_usage;
+ unsigned char sha1[20];
+ const char *arg;
+ int noop;
+ struct option options[] = {
+ OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
+ OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
+ OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
+ OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
+ OPT_INTEGER('m', "mainline", &mainline, "parent number"),
+ OPT_END(),
+ };
+
+ if (parse_options(argc, argv, options, usage_str, 0) != 1)
+ usage_with_options(usage_str, options);
+ arg = argv[0];
+
+ if (get_sha1(arg, sha1))
+ die ("Cannot find '%s'", arg);
+ commit = (struct commit *)parse_object(sha1);
+ if (!commit)
+ die ("Could not find %s", sha1_to_hex(sha1));
+ if (commit->object.type == OBJ_TAG) {
+ commit = (struct commit *)
+ deref_tag((struct object *)commit, arg, strlen(arg));
+ }
+ if (commit->object.type != OBJ_COMMIT)
+ die ("'%s' does not point to a commit", arg);
+}
+
+static char *get_oneline(const char *message)
+{
+ char *result;
+ const char *p = message, *abbrev, *eol;
+ int abbrev_len, oneline_len;
+
+ if (!p)
+ die ("Could not read commit message of %s",
+ sha1_to_hex(commit->object.sha1));
+ while (*p && (*p != '\n' || p[1] != '\n'))
+ p++;
+
+ if (*p) {
+ p += 2;
+ for (eol = p + 1; *eol && *eol != '\n'; eol++)
+ ; /* do nothing */
+ } else
+ eol = p;
+ abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
+ abbrev_len = strlen(abbrev);
+ oneline_len = eol - p;
+ result = xmalloc(abbrev_len + 5 + oneline_len);
+ memcpy(result, abbrev, abbrev_len);
+ memcpy(result + abbrev_len, "... ", 4);
+ memcpy(result + abbrev_len + 4, p, oneline_len);
+ result[abbrev_len + 4 + oneline_len] = '\0';
+ return result;
+}
+
+static char *get_encoding(const char *message)
+{
+ const char *p = message, *eol;
+
+ if (!p)
+ die ("Could not read commit message of %s",
+ sha1_to_hex(commit->object.sha1));
+ while (*p && *p != '\n') {
+ for (eol = p + 1; *eol && *eol != '\n'; eol++)
+ ; /* do nothing */
+ if (!prefixcmp(p, "encoding ")) {
+ char *result = xmalloc(eol - 8 - p);
+ strlcpy(result, p + 9, eol - 8 - p);
+ return result;
+ }
+ p = eol;
+ if (*p == '\n')
+ p++;
+ }
+ return NULL;
+}
+
+static struct lock_file msg_file;
+static int msg_fd;
+
+static void add_to_msg(const char *string)
+{
+ int len = strlen(string);
+ if (write_in_full(msg_fd, string, len) < 0)
+ die ("Could not write to MERGE_MSG");
+}
+
+static void add_message_to_msg(const char *message)
+{
+ const char *p = message;
+ while (*p && (*p != '\n' || p[1] != '\n'))
+ p++;
+
+ if (!*p)
+ add_to_msg(sha1_to_hex(commit->object.sha1));
+
+ p += 2;
+ add_to_msg(p);
+ return;
+}
+
+static void set_author_ident_env(const char *message)
+{
+ const char *p = message;
+ if (!p)
+ die ("Could not read commit message of %s",
+ sha1_to_hex(commit->object.sha1));
+ while (*p && *p != '\n') {
+ const char *eol;
+
+ for (eol = p; *eol && *eol != '\n'; eol++)
+ ; /* do nothing */
+ if (!prefixcmp(p, "author ")) {
+ char *line, *pend, *email, *timestamp;
+
+ p += 7;
+ line = xmemdupz(p, eol - p);
+ email = strchr(line, '<');
+ if (!email)
+ die ("Could not extract author email from %s",
+ sha1_to_hex(commit->object.sha1));
+ if (email == line)
+ pend = line;
+ else
+ for (pend = email; pend != line + 1 &&
+ isspace(pend[-1]); pend--);
+ ; /* do nothing */
+ *pend = '\0';
+ email++;
+ timestamp = strchr(email, '>');
+ if (!timestamp)
+ die ("Could not extract author email from %s",
+ sha1_to_hex(commit->object.sha1));
+ *timestamp = '\0';
+ for (timestamp++; *timestamp && isspace(*timestamp);
+ timestamp++)
+ ; /* do nothing */
+ setenv("GIT_AUTHOR_NAME", line, 1);
+ setenv("GIT_AUTHOR_EMAIL", email, 1);
+ setenv("GIT_AUTHOR_DATE", timestamp, 1);
+ free(line);
+ return;
+ }
+ p = eol;
+ if (*p == '\n')
+ p++;
+ }
+ die ("No author information found in %s",
+ sha1_to_hex(commit->object.sha1));
+}
+
+static int merge_recursive(const char *base_sha1,
+ const char *head_sha1, const char *head_name,
+ const char *next_sha1, const char *next_name)
+{
+ char buffer[256];
+ const char *argv[6];
+
+ sprintf(buffer, "GITHEAD_%s", head_sha1);
+ setenv(buffer, head_name, 1);
+ sprintf(buffer, "GITHEAD_%s", next_sha1);
+ setenv(buffer, next_name, 1);
+
+ /*
+ * This three way merge is an interesting one. We are at
+ * $head, and would want to apply the change between $commit
+ * and $prev on top of us (when reverting), or the change between
+ * $prev and $commit on top of us (when cherry-picking or replaying).
+ */
+ argv[0] = "merge-recursive";
+ argv[1] = base_sha1;
+ argv[2] = "--";
+ argv[3] = head_sha1;
+ argv[4] = next_sha1;
+ argv[5] = NULL;
+
+ return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
+}
+
+static char *help_msg(const unsigned char *sha1)
+{
+ static char helpbuf[1024];
+ char *msg = getenv("GIT_CHERRY_PICK_HELP");
+
+ if (msg)
+ return msg;
+
+ strcpy(helpbuf, " After resolving the conflicts,\n"
+ "mark the corrected paths with 'git add <paths>' "
+ "or 'git rm <paths>' and commit the result.");
+
+ if (action == CHERRY_PICK) {
+ sprintf(helpbuf + strlen(helpbuf),
+ "\nWhen commiting, use the option "
+ "'-c %s' to retain authorship and message.",
+ find_unique_abbrev(sha1, DEFAULT_ABBREV));
+ }
+ return helpbuf;
+}
+
+static int revert_or_cherry_pick(int argc, const char **argv)
+{
+ unsigned char head[20];
+ struct commit *base, *next, *parent;
+ int i;
+ char *oneline, *reencoded_message = NULL;
+ const char *message, *encoding;
+ const char *defmsg = xstrdup(git_path("MERGE_MSG"));
+
+ git_config(git_default_config);
+ me = action == REVERT ? "revert" : "cherry-pick";
+ setenv(GIT_REFLOG_ACTION, me, 0);
+ parse_args(argc, argv);
+
+ /* this is copied from the shell script, but it's never triggered... */
+ if (action == REVERT && !no_replay)
+ die("revert is incompatible with replay");
+
+ if (no_commit) {
+ /*
+ * We do not intend to commit immediately. We just want to
+ * merge the differences in, so let's compute the tree
+ * that represents the "current" state for merge-recursive
+ * to work on.
+ */
+ if (write_cache_as_tree(head, 0, NULL))
+ die ("Your index file is unmerged.");
+ } else {
+ struct wt_status s;
+
+ if (get_sha1("HEAD", head))
+ die ("You do not have a valid HEAD");
+ wt_status_prepare(&s);
+ if (s.commitable)
+ die ("Dirty index: cannot %s", me);
+ discard_cache();
+ }
+
+ if (!commit->parents)
+ die ("Cannot %s a root commit", me);
+ if (commit->parents->next) {
+ /* Reverting or cherry-picking a merge commit */
+ int cnt;
+ struct commit_list *p;
+
+ if (!mainline)
+ die("Commit %s is a merge but no -m option was given.",
+ sha1_to_hex(commit->object.sha1));
+
+ for (cnt = 1, p = commit->parents;
+ cnt != mainline && p;
+ cnt++)
+ p = p->next;
+ if (cnt != mainline || !p)
+ die("Commit %s does not have parent %d",
+ sha1_to_hex(commit->object.sha1), mainline);
+ parent = p->item;
+ } else if (0 < mainline)
+ die("Mainline was specified but commit %s is not a merge.",
+ sha1_to_hex(commit->object.sha1));
+ else
+ parent = commit->parents->item;
+
+ if (!(message = commit->buffer))
+ die ("Cannot get commit message for %s",
+ sha1_to_hex(commit->object.sha1));
+
+ /*
+ * "commit" is an existing commit. We would want to apply
+ * the difference it introduces since its first parent "prev"
+ * on top of the current HEAD if we are cherry-pick. Or the
+ * reverse of it if we are revert.
+ */
+
+ msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
+
+ encoding = get_encoding(message);
+ if (!encoding)
+ encoding = "utf-8";
+ if (!git_commit_encoding)
+ git_commit_encoding = "utf-8";
+ if ((reencoded_message = reencode_string(message,
+ git_commit_encoding, encoding)))
+ message = reencoded_message;
+
+ oneline = get_oneline(message);
+
+ if (action == REVERT) {
+ char *oneline_body = strchr(oneline, ' ');
+
+ base = commit;
+ next = parent;
+ add_to_msg("Revert \"");
+ add_to_msg(oneline_body + 1);
+ add_to_msg("\"\n\nThis reverts commit ");
+ add_to_msg(sha1_to_hex(commit->object.sha1));
+ add_to_msg(".\n");
+ } else {
+ base = parent;
+ next = commit;
+ set_author_ident_env(message);
+ add_message_to_msg(message);
+ if (no_replay) {
+ add_to_msg("(cherry picked from commit ");
+ add_to_msg(sha1_to_hex(commit->object.sha1));
+ add_to_msg(")\n");
+ }
+ }
+
+ if (merge_recursive(sha1_to_hex(base->object.sha1),
+ sha1_to_hex(head), "HEAD",
+ sha1_to_hex(next->object.sha1), oneline) ||
+ write_cache_as_tree(head, 0, NULL)) {
+ add_to_msg("\nConflicts:\n\n");
+ read_cache();
+ for (i = 0; i < active_nr;) {
+ struct cache_entry *ce = active_cache[i++];
+ if (ce_stage(ce)) {
+ add_to_msg("\t");
+ add_to_msg(ce->name);
+ add_to_msg("\n");
+ while (i < active_nr && !strcmp(ce->name,
+ active_cache[i]->name))
+ i++;
+ }
+ }
+ if (commit_lock_file(&msg_file) < 0)
+ die ("Error wrapping up %s", defmsg);
+ fprintf(stderr, "Automatic %s failed.%s\n",
+ me, help_msg(commit->object.sha1));
+ exit(1);
+ }
+ if (commit_lock_file(&msg_file) < 0)
+ die ("Error wrapping up %s", defmsg);
+ fprintf(stderr, "Finished one %s.\n", me);
+
+ /*
+ *
+ * If we are cherry-pick, and if the merge did not result in
+ * hand-editing, we will hit this commit and inherit the original
+ * author date and name.
+ * If we are revert, or if our cherry-pick results in a hand merge,
+ * we had better say that the current user is responsible for that.
+ */
+
+ if (!no_commit) {
+ if (edit)
+ return execl_git_cmd("commit", "-n", NULL);
+ else
+ return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
+ }
+ if (reencoded_message)
+ free(reencoded_message);
+
+ return 0;
+}
+
+int cmd_revert(int argc, const char **argv, const char *prefix)
+{
+ if (isatty(0))
+ edit = 1;
+ no_replay = 1;
+ action = REVERT;
+ return revert_or_cherry_pick(argc, argv);
+}
+
+int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
+{
+ no_replay = 0;
+ action = CHERRY_PICK;
+ return revert_or_cherry_pick(argc, argv);
+}